I think setting up the specs for a laptop is far more individual than for a desktop or a server. For me, the emphasis would be thus:
1. Extreme battery life
2. Very light
3. Thin
4. Cool (meaning, NOT hot)
All of which indicate a FlashRAM-based laptop.
5. Light and sturdy enclosure
6. Widescreen
For me, power is not that important; ease of use on the go is.
I absolutely disagree that 10.2 was the Greatest Upgrade and that 10.3 was merely an update. For my money (!), though 10.2 made OSX usable, it was 10.3 that made the whole concept of OSX useFUL. The point mentioned about the underlying structure of 10.3 being the main improvement is absolutely true, and the significance thereof becomes evident when you look at how many MAJOR improvements have been introduced in the following point releases (10.3.1-9). On top of that, basic code optimization really took off with 10.3, and running 10.3.9 against any 10.2 version makes you wonder why anyone even bothered back then. By now, using XPostFacto, 10.3.9 running on my 233MHz PDQ is actually PLEASANT to use - something I would have foresworn could ever be said about OSX. Now, if only the developers would focus on bringing back coherence and internal logic into the new UI concept they are building (just wait until you use Exposé, Spotlight and Automator together; THEN you will agree that Apple has finally made it past the OS8 and NeXT paradigms), and then I can retire a happy man.... :-)
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